Abstract/Project Summary Proposed Supplement: We will add a new module on Alzheimer's Disease and Related Dementias (ADRD) to the microsimulation model developed in the parent grant. Our current project studies how interventions on risk factors like obesity, diet, and physical activity affect incidence and prevalence of chronic conditions like hypertension, diabetes, or stroke. These health conditions in turn affect health and long-term care needs, quality of life, disability, and mortality. So far, our model does not include any measures related to ADRD. However, many of the conditions and pathways modeled in the parent grant have also been implicated in ADRD. The supplement will add ADRD as an additional outcome dimension. Adding ADRD necessitates some restructuring and incorporating other data, but is a natural extension using the same architecture as the original project. Our specific aims for the supplement are to: 1. Incorporate cognition and ADRD measures from the Health and Retirement Survey 2. Validate the new ADRD modules and assess statistical uncertainty 3. Expand our visualization tool for ADRD outcomes 4. Simulate population outcomes related to ADRD and predict burden of ADRD with and without interventions targeting diet, physical activity, or obesity. Innovations of this supplement will be: 1) the first microsimulation model to link population interventions in diet/physical activity/obesity to ADRD outcomes; 2) the first microsimulation model on ADRD that assesses statistical uncertainty for statistical inference beyond point estimates. Aims of Current parent grant: The prevalence of obesity has increased dramatically over the last three decades, as has its corresponding burden of disease. Much of that burden is preventable. There is no shortage of suggestions how to address the obesity epidemic ? the gap is how to assess the likely long-run effects of intervention. As the ultimate outcomes of interest (prevention of chronic illness at the population level) will not manifest for many years following an intervention, mathematical models like the one we develop in this project are needed to integrate the information from multiple sources. Without good simulation models, it is difficult ? if not impossible ? to make predictions of socially important outcomes of prevention efforts, most of which are many years in the future and beyond the scope of clinical trials. The specific aims are: (1) Develop, test and validate a dynamic microsimulation modeling platform that captures individual and social dynamics of diet/nutrition, physical activity, and BMI; (2) Use the platform to predict health, social and economic outcomes for the coming decades; (3) Assess the outcomes consequences of health policies in multiple areas (food taxes and subsidies, labeling laws, bariatric surgery) at reducing social harms; (4) Provide an open version to researchers and policy makers to conduct their own calculations.